Donald Trump's surprise courting of Sarah Palin, as well as the GOP's continuing attacks on him, are the catalysts helping the billionaire developer's meteoric rise in the polls, conservative pundit Patrick J. Buchanan tells Newsmax TV.

And Buchanan, who served as a senior adviser to Presidents Richard Nixon, Ronald Reagan and Gerald Ford, also believes Trump is doing so well that he'll likely end up as one of the final four contenders in line for the Republican presidential nomination.

"The other Republicans — by attacking him and piling on and joining the media establishment in beating up on him, calling him unacceptable — they're enhancing his credentials as someone the establishment desperately opposes more than anyone else in the race," Buchanan said Wednesday on "The Steve Malzberg Show."

"And that attracts people to him. They are building up his constituency."

Buchanan, a former GOP presidential candidate himself, added that Trump's embrace of Palin, the former governor of Alaska and vice-presidential running mate of Sen. John McCain in 2008, is also big plus. Trump, who questioned McCain's status as a war hero, says Palin would be an excellent choice for his cabinet.

"The fact that he brings up Sarah Palin in the Cabinet, or that she is a gal that he can work with and he admires her point of view and the rest of it, that helps him with his constituency," Buchanan said.

"Now, there's some folks who obviously on the other side, the establishment, would say, good heavens that really makes it impossible for us to move to him.

"By and large, that probably helps him with his core constituency. She still has a tremendous following. She may be underwater in the polls, like almost everybody is, but she's still got a following."

For weeks, Trump has remained well ahead of all other Republican candidates in the polls — despite his straight-talking, shoot-from-the-lip style that has infuriated the party.

Twenty-six percent of 1,902 Republicans surveyed said they would vote for Trump, versus 20 percent for Bush and 10 percent for Rubio. Twelve percent would vote for Wisconsin Gov. Scott Walker, while 16 percent said they were undecided or would vote for a candidate not named in the poll.

And a Monmouth University poll released Tuesday shows Trump crushing fellow Republicans in New Hampshire, where he has double the support of Bush, among voters likely to participate in the Granite State primary. Trump's 24 percent support bests Bush’s 12 percent in the poll of 467 New Hampshire voters expected to vote in the Republican primary.

And Buchanan believes Trump will likely make it all the way to the end of the contest.

"Trump certainly is going to be in the final four if he doesn't implode somehow for some reason between now and January 1. And if he's in the final four, I see him getting down to the final two because I can't see two centrist, establishment Republicans beating him," Buchanan said.

"But I do think this race always comes down to a centrist, establishment, Republican against the outsider and it looks to me like Donald Trump has got that outsider slot."

Last week, Trump warned the Republican Party that unless they treated him fairly, he would consider running as a third-party candidate — a threat that would likely help Democratic frontrunner Hillary Clinton's bid for the White House.